Liquid crystal display (LCD) devices are characterized by low power consumption, low radiation and low manufacturing cost, etc., and have been widely used in various types of electronic devices such as display devices, television (TV) sets, cell phones, digital cameras, and other digital electronic devices. Liquid crystal display devices primarily include display panels and signal boards which supply signals to the display panels. The signal boards, for example, may include system boards and TCON (timing controller) boards.